Acacia
聽is now drawing to a close. The season in the D鈥檋arawal calendar aligning with August, the last month of winter is behind us.聽聽is known to be cold and windy, and I remember it so for decades. My mother said August is a bad month. For someone of her vintage this was true, as not only is the weather cold and windy, but the number of deaths from influenza was higher in August than in the preceding two months, reflecting a pattern of sense-making in our temporal memories. In this case, anticipating news of loss.
For thousands of years human survival has been contingent on recognition of temporal and spatial patterns in the landscape, events that coincide with the flowering of a particular plant species, on attributing cause and effect, on anticipating what will happen next. Human survival is contingent on botanical literacy.
At this time, the Earth is not tilting rapidly, although enough to notice. The Southern Hemisphere moving closer to the sun. The days lengthen. Ocean and air currents respond to temperature changes. Biota acclimates. Reproductive cycles turn. Seasonal biological patterns repeated every year, biodiversity intertwined with biogeography manifesting as temporally dynamic landscapes across the continent. A time for reflection.
For thousands of years human survival has been contingent on recognition of temporal and spatial patterns in the landscape, events that coincide with the flowering of a particular plant species, on attributing cause and effect, on anticipating what will happen next. Human survival is contingent on botanical literacy.
For Wiritjiribin, two聽Acacia聽species are offered as bookends. The flowering of Boo鈥檏errikin (Acacia decurrens)聽augurs the start of the season. This is when the fish start to run. The flowering of Marrai鈥檜o (A. floribunda) augurs the end of Wiritjiribin and so the beginning of the next season, Ngoonungi (September 鈥� October). This is when the rains of spring usually begin. The D鈥檋arawal calendar features聽础肠补肠颈补听spp. for the seasons between the equinoxes, Kai鈥檃rrewan (A. binervia)聽the time of Parra鈥檇owee (November 鈥� December), when it is warm and wet, and the eels migrate to the ocean. Weetjellan (A. implexa) flowering indicates Burran (January 鈥� March) when it is hot and dry. Meat is not eaten at this time as it spoils so readily in the heat.
Given our national flower is A. pycnantha 鈥� considered a symbol of unity 鈥� the significance of the Acacia genus extends across the continent by virtue of this fact alone. There is more to discover about Acacia species.
Plants, specific plants, communicating key information with humans via their phenologies. Of course, there are more than these four聽Acacia聽species, in fact there are more than 1,000 different聽础肠补肠颈补听species endemic to Australia, many (most) with highly specific distributions. Subtleties in locations inviting speciation, leading to diversification and ecosystem complexity established over, in the case of聽Acacia, approximately 25 Mya.
Given our national flower is聽A. pycnantha聽鈥� considered a symbol of unity 鈥� the significance of the聽Acacia聽genus extends across the continent by virtue of this fact alone. There is more to discover about Acacia species. I have recently read with great delight that 鈥渢he power from the heavens鈥� can manifest as gum 鈥済um in the hearts of wattle trees鈥�, this gum being 鈥渕ade by shooting stars lodging there and breaking into bits鈥� (). The inclusion of cultural knowledge of Aboriginal and Torres Strait Islander peoples affords deeper significance to these kinds of plant-human relationships. Further, based on the importance of Acacia to many Aboriginal people, Amnesty International proposed Australia Day be changed to 1 September, or Wattle Day, the first day of National Biodiversity Month.
Biodiversity is often explained in terms of a scientific measure to enable comparisons of species richness across time and place. By and large these measures monitor our own ecosystem vandalism. More recently, and reflecting our human-centredness, biodiversity is linked with human wellness (see聽) to focus on the importance of 鈥榚cosystem services鈥�.
Humans, as ever, sitting at the heart of the importance of this genus. With reference to聽础肠补肠颈补听spp., much of the readily available information about聽础肠补肠颈补听spp. lists the uses of various聽础肠补肠颈补听sp. as medicine, food, and wood for the making of artefacts.
Barely a nod is given to the flowering patterns of聽础肠补肠颈补听spp. being important to effective reading of the landscape and ensuring survival.
As I read the 2021 State of the Environment report鈥檚聽聽I wonder about how the glorious complexities of ecosystems are represented in reports; condensed, simple, readily digestible, largely offering depressingly downward trends. There is so much that we do not know; we are facing uncertainty and surround ourselves in an armour of metrics. Of course, our records are incomplete. Not all species have been documented, nor ever will be.
What we do know for sure is the number of extinctions events in Australia since colonisation is an under-representation (). Action plans are crucial if we are to slow the frequency of extinctions.聽聽have devised the National Action Plan for Imperiled Plants, where three of the 50 imperiled species listed are聽础肠补肠颈补听spp. This action plan makes it clear that there are ways to intervene to redress the injustice of extinction and conservation is key.
A locally important example is the Eastern Suburbs Banksia Scrub (ESBS). At the end of last year, this ecological community was reclassified by the聽聽as 鈥樎燨ffering refugia for the plants that comprise the ESBS in urban gardens is crucial to maintain genetic diversity of these remnant populations.
For as much as I am proud of the work we are doing in creating vegetation refugia, I grieve for the plants we have lost. These human-driven extinctions, these erosions of biodiversity, lost opportunities to learn about vegetation of this vast and wondrous continent.
In our own聽聽on the grounds of the University of Sydney we have focused on the Eastern Suburbs Banksia Scrub (ESBS). To date, three ESBS聽础肠补肠颈补听spp. have been planted (i.e.,聽A. longifolia, A. suaveolens, A. ulicifolia).聽The garden was recently shortlisted for the聽.
Like my mother before me, and in light of the State of the Environment report, I have found August to be a time of grief. For as much as I am proud of the work we are doing in creating vegetation refugia, I grieve for the plants we have lost. These human-driven extinctions, these erosions of biodiversity, lost opportunities to learn about vegetation of this vast and wondrous continent.
Associate Professor聽Rosanne Quinnell聽is Deputy Director (Education) in SEI and a scientist and educator in the聽School of Life and Environmental Sciences, University of Sydney. She has taught botany for close to 25 years and is deeply committed to improving student engagement in science, particularly engagement with the botanical world by improving the botanical literacy within and outside of the classroom. Rosanne is redeveloping聽聽in collaborating with聽DVC ISS, ICT and聽聽with the re-release due before the end of 2022. Rosanne co-designed the聽聽in partnership the University Grounds staff and the Sustainability Strategy (planted 2021). Rosanne is leading the Living Laboratory in partnership with the University鈥檚 Sustainability Strategy, and she is an active member of the聽Sydney Indigenous Research Network.
Header image:聽Wattle by Anthony Rae via Unsplash.